How to use the cone frustum calculator
Find volume of a truncated cone. Enter bottom radius, top radius, height in the fields above; the volume, slant height are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- r1 — Bottom radius
- r2 — Top radius
- h — Height
Worked example
With bottom radius = 5, top radius = 3, height = 8, the calculator gives volume ≈ 410.5014; slant height ≈ 8.246211.
Frequently asked questions
What is the formula for the cone frustum calculation?
Volume = π × h × (r1 × r1+r1 × r2+r2 × r2) / 3. Slant height = hypot(r1-r2,h). Here r1 is bottom radius, r2 is top radius, h is height.
What inputs do I need for the cone frustum calculator?
You need bottom radius, top radius, height. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.